Project Summary Nonalcoholic fatty liver disease (NAFLD) is a chronic liver disease that affects 10-30% of children in the United States. NAFLD is surprisingly aggressive in children and there is currently no approved therapy for it. Because the onset of NAFLD is often in young children (8-12 years), any potential therapeutic for NAFLD will need to be almost risk-free. In this proposal, we seek to study IMM-124E, a medical product that was initially developed for traveler?s diarrhea and has been available over the counter in Australia for years. IMM-124E is a hyperimmune bovine colostrum manufactured by drying the cow?s first milk and packaging it into caplets. This hyperimmune ?milk powder? is enriched with IgG against E. coli bacterial products (LPS) by vaccinating the pregnant cow. Because altered microbiome, increased gut permeability, and increased LPS have been shown to be important in the mechanism of NAFLD, IMM-124E has logical support for efficacy in NAFLD. Phase I studies in adults have shown improved insulin resistance, liver enzymes, and promotion of regulatory T-cells. This proposal is designed to test IMM-124E in a small phase II study in children with NAFLD in order to assess preliminary efficacy and safety endpoints and to improve understanding of the mechanisms. This will be accomplished through two aims in a 12 week double-blind, randomized, placebo-controlled clinical trial in children with NAFLD. Aim 1 will determine if 3 months of treatment with IMM-124E in combination with lifestyle changes (standard of care (SOC)) results in greater improvement in 1) hepatic lipid and inflammation, 2) insulin sensitivity, 3) blood lipids, in children with NAFLD, compared to placebo with SOC as well as monitor safety related endpoints. Aim 2 will define mechanisms of action-related endpoints including: stool microbiome, metabolomics, LPS and transcriptomics of innate immune response genes and correlate these with changes in clinical measurements. The proposal leverages state-of-the art platforms at Emory University including high throughput, high resolution metabolomics and established centers for microbiome and transcriptomics to accomplish the mechanism studies. Additionally, we have the clinical population to quickly enroll children into this trial. This proposal addresses the mission of the NIH NCCIH and NICHD by rigorously investigating a complementary treatment with the potential to improve health for large numbers of children. If successful, these studies would support designing a future large scale phase III trial. These studies will enhance our understanding of the role of the gut in pediatric NAFLD and if positive, will result in a low risk, low side effect, high yield therapeutic for pediatric NAFLD.